I have a 1989 oldsmobile royale brougham delta 88. My car wont start and none of the lights turn on. My car wont lock automatically. The battery still has juice in it. Idk what to do. Fuses are good.

Check fuses. There's normally an ECU fuse or main fuse under hood. Now I also remember those cars had issues with ground from battery. Check and clean all ground contacts which involves battery,engine and frame!

If your battery has "juice" (more than 13-16 volts then it has nothing to do with you alternator. Alternator only charges battery car is ruining.

Agreed check your ground on the frame and on the Block also no side post make sure you got them threaded in there good I've done that before make sure you got 12 volts coming out of that battery remember your battery starts your car your alternator runs your car check all your cables you got a bad connection somewhere and make sure you when you say it has juice how much juice big difference between 5 volts and 12 volts you can always pull out your door lock or your window switch and see how much current you're getting to that source with a meter or if you got a test light see if your getting any of anything at all back to that point just this past summer I had a bad ground on my tail lights at 12 volts coming out of my battery 12 volts come out a alternator what y'all haters new the battery is a year-and-a-half-old but I had 12 volts going all the way but not in my lights and it turned out as a bad ground it just corroded at the connection I just cleaned out my ground wire and relocated it my ground for my lights is now contained Road debris and ate it up and it got loose

Transmission and pvc conection repair

We put a brand new battery in alternator but it still don't want to keep charge or what's the problem